Semiconductor device fabrication employs, for example, ion implantation in which impurity ions are introduced into a semiconductor substrate to impart an n or p conductive type using a photoresist pattern as a mask. In the ion implantation, the impurity ions are implanted directly into a semiconductor substrate or implanted through a thin film formed on the surface of the semiconductor substrate, by using ion implantation equipment (ion doping equipment). The photoresist pattern is then removed by, for example, wet cleaning using sulfuric acid and hydrogen peroxide water, wet cleaning using aqueous ammonia and hydrogen peroxide water, or ashing.
A technique has been known to enable formation of a photoresist pattern having a desired shape by applying an anti-reflective coating forming composition onto a semiconductor substrate, baking the composition to form an anti-reflective coating (resist underlayer film), and forming a photoresist pattern thereon (Patent Document 1, for example). An anti-reflective coating formed from a composition containing a high molecular compound including phosphorus atoms is also known (Patent Document 2). A phosphorus atom is a representative example of a donor contained in an n-type semiconductor. However, ion implantation into a semiconductor substrate through the aforementioned anti-reflective coating has not been preferred. This is because impurities contained in the anti-reflective coating may penetrate the semiconductor substrate to cause adverse effect on a semiconductor device to be fabricated.